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101.
This paper studies a new steady‐state simulation output analysis method called replicated batch means in which a small number of replications are conducted and the observations in these replications are grouped into batches. This paper also introduces and compares methods for selecting the initial state of each replication. More specifically, we show that confidence intervals constructed by the replicated batch means method are valid for large batch sizes and derive expressions for the expected values and variances of the steady‐state mean and variance estimators for stationary processes and large sample sizes. We then use these expressions, analytical examples, and numerical experiments to compare the replicated batch means method with the standard batch means and multiple replications methods. The numerical results, which are obtained from an AR(1) process and a small, nearly‐decomposable Markov chain, show that the multiple replications method often gives confidence intervals with poorer coverage than the standard and replicated batch means methods and that the replicated batch means method, implemented with good choices of initialization method and number of replications, provides confidence interval coverages that range from being comparable with to being noticeably better than coverages obtained by the standard batch means method. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
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多目标规划是一类重要的优化模型,有着广泛的实际应用,但其求解至今仍是运筹学的一个难点.针对一般约束多目标优化问题,在设计了新的适应度函数和选择算子的基础上,提出一种新型多目标遗传算法.将其应用于导弹对集群目标射击效能优化问题,验证了算法的有效性. 相似文献
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Yoad Shefi 《Defence and Peace Economics》2013,24(6):427-448
This paper models the interactions between the defense industry market structure and the defense needs of Israel, the USA and Western Europe, which produce several heterogeneous defense goods. The model specifies that the defense industries of the US and Europe are ‘large’ while that of Israel is ‘small’. The US military aid to Israel is also an integral part of the model. The results show that net defense costs of Israel are minimal when the number of its defense firms is one. The model predicts that an increase in US military aid reduces Israel’s government expenditure, its defense industry’s profits and its net defense costs. 相似文献
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This paper models the interactions between the defense needs of the USA and Western Europe, which produce several heterogeneous defense goods, and the defense industry market structure. The results show that net defense costs of the USA and Europe are lower when the number of defense firms in each arms‐producing country is small and when the world prices of the defense goods are high. The model predicts that the increase in world prices will crowd‐out countries in the developing world from the market for modern weapon systems and may force them to develop and use ‘cheap and dirty’ weapon systems. 相似文献
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Nicholas Apergis Matteo Bonato Rangan Gupta Clement Kyei 《Defence and Peace Economics》2013,24(6):684-696
AbstractWe use the k-th-order nonparametric causality test at monthly frequency over the period of 1985:1 to 2016:06 to analyze whether geopolitical risks can predict movements in stock returns and volatility of 24 global defense firms. The nonparametric approach controls for the existing misspecification of a linear framework of causality, and hence, the mild evidence of causality obtained under the standard Granger tests cannot be relied upon. When we apply the nonparametric test, we find that there is no evidence of predictability of stock returns of these defense companies emanating from the geopolitical risk measure. However, the geopolitical risk index does predict realized volatility in 50% of the companies. Our results indicate that while global geopolitical events over a period of time is less likely to predict returns, such global risks are more inclined in affecting future risk profile of defense firms. 相似文献
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Since the post-World War II genesis of nuclear deterrence, two presidential initiatives have been presented to deliver humanity from the threat of its failure. The first was the Strategic Defense Initiative (SDI), a constellation of space- and ground-based systems that President Ronald Reagan envisioned would render nuclear weapons “impotent and obsolete.” The second is President Barack Obama's roadmap to “a world without nuclear weapons,” commonly referred to as “Global Zero.” While these proposals appear to have little in common, deeper investigation reveals a number of provocative similarities in motivation and presentation. Moreover, both generated fierce debate, often with ideological overtones, about their strategic desirability and technical feasibility. We use these parallels, as well as prominent dissimilarities, to draw lessons from the SDI experience that can be applied to the debate over Global Zero. 相似文献
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